Designs have been unveiled for what will be the tallest building in the City of London, 1 Undershaft.
Designed by Eric Parry to sit on what is presently the Aviva Tower overlooking St Helen's Plaza in the city of London, the 73-storey building will be largely office space with the upper level being a double height observation floor peaking above the roof of 22 Bishopsgate that will actually be free for everyone to use, and without the need to book unlike the compromised 20 Fenchurch Street. At the heart of this observation level will be a diaorama showing the history of London, and a spiralling walkway around it.
The height of the building will be 309.6 metres AOD, which when taking into account a ground level of about 18 metres above sea level means that the ground to roof height should be about 291 metres, 13 metres taller than that of 22 Bishopsgate. This makes it in terms of height above sea level, the same as that of the Shard, the maximum that the Civil Aviation Authority will permit. Originally a crown was also proposed for the top of the tower, but this was dropped following the objections from the planners of the City of London.
In total there will be about 90,000 square metres of floor space within the scheme for 10,000 workers, and 1,800 square metres will be in a basement with retail and restaurants that will have been excavated with a huge mezzanine space in the middle. Keeping the project as car-free as possible there will be 1,500 cycling spaces with the necessary showers to keep such a large amount of people sweat free for a day in the office.
The design itself consists of regular floor-plates, which are hugely efficient thanks to the offsetting of the core to the west that allows them to be as expansive as possible and a profile that tapers gradually as it rises.
At ground level the tower is opened up to the area around it following on from a similar approach at the neighbouring Leadenhall Building with a ten metre tall semi-public void. In this case massive corner columns of Cor-Ten steel connect with the ground, and these super columns help provide increased structural support. Connecting them together is a diagonal grid of cross-bracing, again made of Cor-Ten.
The project is being developed by Aroland Holdings Limited, a Singapore-based property firm who intend to submit a planning application in the new year.